A new coupling system hitch between a towing vehicle and a towed trailer which is self-aligning, self-connecting, and which allows for maximum horizontal and vertical movement of the towed vehicle relative to the towing vehicle. Unlike the standard ball and socket hitch, the coupler ring hitch assembly consists of two fundamental parts: (1) a coupler ring guide and a housing, the latter having a rearward extending rectangular shaft for attachment to the towing vehicle by insertion of said shaft into a Class II or III trailer hitch channel; and, (2) a double-ring coupler assembly which is guided by a flanged coupler guide into a spherical housing. The coupler ring assembly is held in place by a coupler pin which extends vertically through the spherical housing and through the double ring coupler. Extending from and operatively associated with the spherical housing are flanged walls which diverge rearwardly guiding the coupler ring assembly into the spherical housing. The coupler ring assembly extends outwardly into a rectangular shaft which fits over and is bolted onto the tongue of a towed trailer. The coupler ring assembly consists of an inner ring which is geometrically similar to a lateral section of a sphere. The inner ring is housed within a similarly shaped outer ring in such a way that the outer ring is allowed to rotate three dimensionally about the inner ring thus allowing maximum vertical and horizontal movement of the tongue and towed trailer within the flanged walls of the coupler guide. The double ring coupler assembly allows a maximum and substantial improvement to the range of motion both vertically and horizontally of the trailer tongue and trailer.